In a multipolar connector for transmitting high-speed differential signals, when differential signal terminals and other terminals (for example, non-paired terminals (i.e., terminals except terminals of a terminal pair) such as a power source terminal and a ground terminal) are arranged at regular pitches, the coupling force between the differential pair cannot be sufficiently ensured, and the transmission mode becomes similar relatively to the single mode. As compared with the differential mode transmission, the single mode transmission is inferior in various characteristics such as the signal speed, the skew, and noises. When the pitches are simply narrowed in order to enhance the coupling force, the impedance is excessively lowered by influence of the other terminals with respect to other impedances to be used together, or a standard value. In a connector portion of a 100-ohm differential impedance system, therefore, the differential mode transmission is hardly realized at the regular pitches.
On the other hand, Patent Literature 1 discloses a terminal structure where differential signal terminals are made different in width or bent, whereby the pitch gap of contact portions of the differential signal terminals which are to be connected to counter terminals is made narrower than that between the contact portions of the differential signal terminals and contact portions of other terminals adjacent to the differential signal terminals.